Unit converter
Gigabytes to Megabytes Converter
Turn gigabytes into megabytes in one step. In the decimal (SI) system that storage makers and mobile networks use, one gigabyte equals exactly 1,000 megabytes, so the sum is a clean multiply by 1,000. Enter a figure in GB and the tool returns the matching MB, with a lookup table for the sizes people check most. This pairing comes up everywhere day to day: reading a mobile data allowance against the size of an app download, working out how many photos fit on a memory card, or seeing whether a video file will sit inside a cloud quota.
1 gigabyte = 1,000 megabytes
Common gigabytes to megabytes values
| Gigabytes | Megabytes |
|---|---|
| 1 GB | 1,000 MB |
| 2 GB | 2,000 MB |
| 5 GB | 5,000 MB |
| 10 GB | 10,000 MB |
| 20 GB | 20,000 MB |
| 50 GB | 50,000 MB |
| 100 GB | 100,000 MB |
How to convert
- Begin with the amount of data in gigabytes.
- Multiply by 1,000, since one gigabyte holds 1,000 megabytes on the decimal scale.
- The product is that same amount written in megabytes.
- Reverse the sum by dividing megabytes by 1,000 to land back on gigabytes.
- Quick head maths: shift the decimal point three places to the right, so 2.5 GB reads as 2,500 MB.
megabytes = gigabytes x 1000
The decimal gigabyte is one thousand megabytes, so a value in GB scales up to MB by multiplying by 1,000. Going the other way means dividing MB by 1,000. Because the factor is a power of ten, the conversion is just a shift of the decimal point.
- GB
- the amount of data in gigabytes
- 1000
- megabytes in one decimal gigabyte
Worked example
A 4 GB mobile data bundle is 4 multiplied by 1,000, which comes to 4,000 MB. Against that, a 250 MB app update uses 250 of those megabytes, leaving 3,750 MB of the bundle before the month is out.
Key facts
- One decimal gigabyte is 1,000 MB; one gibibyte is 1,024 MiB.
- A typical hour of standard-definition streaming uses roughly 700 MB, about 0.7 GB.
- A 64 GB phone advertises around 64,000 MB of raw capacity before formatting.
- Email attachments are often capped near 25 MB, which is 0.025 GB.
Tips
- When comparing a data plan to download sizes, convert the plan to MB first so both numbers share a unit.
- Round download estimates upward a little, because protocol overhead and retries add to the headline file size.
Frequently asked questions
How many MB are in 1 GB?+
On the decimal scale used by drive makers and carriers, one gigabyte is 1,000 megabytes. In the binary scale a gibibyte (GiB) is 1,024 mebibytes, which is a separate unit.
Is it 1000 or 1024?+
This tool uses 1,000, the SI definition for the gigabyte and megabyte. Operating systems that report 1,024 are actually measuring gibibytes and mebibytes while labelling them GB and MB.
How many MB is half a gigabyte?+
0.5 GB equals 500 MB. Three quarters of a gigabyte is 750 MB.
Why does my phone show fewer MB than advertised?+
Formatting and system files reserve space, and the device may count in binary, so the usable figure often sits below the round decimal number on the box.
Things to watch
- Software that reports storage in binary uses 1,024 per step, so its GB and MB figures will not match this decimal conversion exactly.
Sources
Last updated: 2026-01-01
Conversions use internationally defined factors. Provided for general use; verify critical measurements independently.